Educational device



y 31, 1932- F. J. SEWALL EDUCATIONAL DEVICE Filed Oct. 11, 1929 Patented May 31, 1932 I FRANK J. sEw LL, or: COLUMBIALTA, oHIo EDUCATIONAL DEVICE Applicationfiled October 11,. 1929. SerialNd. 398,997,

object of niy invention is toiprovide a 7 I reading or display opening, 13, which'oextends "mechanical device or meansby-which, for

' teaching purposes, mathematical operations can-be performed both arithmetical and algebraioal, by exhibiting Aproblemssand answers, f0r example, and which isinexpensive and easily operated, ZLIKl' WlIlCll 1n itsconstruction and manipulation will be attractive r or inviting to children-and which will be suitable for use in the home as well as in school 7 rooms I My, inventionconsists in whatever is de-; scribed byorisinclud'ed within the terms or scope of the appended claims;

' In the drawings F ig.r l'is a perspective view of a teaching" to leave .them'at rest therefor readingr device embodying my invention" with a portion of theouter casing broken away and internal partsshown in dotted lines Fig; 2 is a vertical section thereof; -v Fig.3 is a detail view in-perspective ofthe band feeding device and the symbol plates 'carried thereby; Figg l. is a detail View in section showing anarrangement for the use of electric lights as a substitute for the blind device,

.Describing the "embodiment of my inven :tion shown in the drawings it comprises a rec- 'tangular cabinet or casing, 10, within which at top and bottom are journaled-horizontal parallel rollers, 11, over and betweenwhich extends an endless band or apron, 12,,of suit-' able inexpensive fleirible material upon the a outer surface of which'are numbers in three spaced apart vertical columns; the numbers of the respective columns alining horizontally and the numbers in each horizontal row" having an arithmetical or mathematical relation such as the'multiplierand multipliocandian'dthe product, that is to say that relation which members have in the perform- 1 ancefof arithmetical oralgebraical operations. Some of the alining numbers maybe algebraicah While one device orgappliance 'may have provision for a large number of mathematical operations, my invention, may be embodied in a device providing for a less 'cludes a knob which is situated at" the front the ratchet.

vafterwards the third numeral orflsymbol number, this matter being regulated by the,

In the upper part of the casing frontiisia horizontally fromi side to side to and' past whic'hthenumerals or symbols on the endless bankare mov'edstep by step or intermittently r is movedcby one reciprocation of the pawl :bar, 14, far enough to bring a horiz0ntalr0wi of symbols r opposite thesight opening, 13,

.To reciprocate the pawl-carrying bar, 14, ithas a handle, 17, attached to it whichin-z Q of the casing: close to thev side thereof: :This

situation: isto; enable pawl 'bar,v14, to be actuated as by a teacherso that no portioniof his body need be in front of the device and so I cover what appears atthe reading orisightl opening. ,o

Inasmuch as it may be desirableto rapidly I move thefsymbobcarrying; band or apron and for an indefinite extent, I provide; a

turning knob, 18, .on the right side of theya casing which is connected with the shaft or pivot of the lower roller, l1,'and which-may turn it ineither direction; Ifneedfulthe pawl bar may be liftedsby its handle from 1 For stating the problems to be-solved,but

two of three alining numbers or symbols are exposed at the sight, opening, l3, then which gives the solution is exposed,- the solution then appearing being first covered by, a

, blind thatyconsistsiof a plate which carries on its face aquestion mark or interrogation 1 point and that blindis attached to andmovable with the pawl bar, 14, fsoithjat by the retracting or non-feeding movement of the bar,'l4, the blind is moved from over the solution and its return; to concealing eposi- 7 tion is simultaneously effected by'the feed- 1 ingmovement Of t e pawl bar. 14, forv statal i that oppositely extending horizontal slots,

20, iirtherespective plates may be placed one over the other producing a comparatively short opening and they may be drawn out producing a long opening and exposing when so drawn out, the interrogation or question mark on each. \Vhen they are slid together finding of base rate and percentage.

only one interrogation mark appears. Said lates, 19, are carried by and are horizon- :tally slidable crosswise of an open frame, 21, which is attached to and extends horizontally from the'upper endof the pawl-carrying bar, 14, and which has a lengthsuch that the blind plates maybe shifted into cooperative relation with any desired vertical row or rows of numerals or symbols on the band or apron. I p I Situated forward of the blind plates and.

their supporting frame is a plate,'22, that is slidably secured to the inner side of the casing front orcover so that it may be moved vertically to placein alinement with the sight o ning, 13, and theslots, 20, 'of the blind tes, anyone of an assortment of slots, 23, ormedin the plate in horizontal groups of three, one .abovethe other, such slots of two groups beingdisposed relatively to one another according to the arithmetical operation :to be performed, and the slots ofthe third. roup being lengthened to'expose'the symbo of an algebraicproblem, which symbols are longer than the mere numerals for an arithmetical operation. To enable both multiplication and addition or their equivalents to be performed in the same device, it

isnecessary to have certain of the numerals,

vused in those respective operations, in different columns that extend over the apron in different vertical planes, .these columns being spacedla'terally apart and for that reason the slots, 23, for multiplication and 7 addition :are placed out of alinem'ent vertically as clearly shownin Fig. 1' of the drawings, so that they will cooperate with their res tive columns of numerals.

.or-sliding the plate 22, vertically to expose the severalgroups of slots, 23, at the sight opening, 13, I attach to the plate near each side a button, 24, which extends outward'through a vertical slot, 25, in the front wall foraccess and saidbuttonis preferably a clamping device so that the two buttons may be used to clamp or fix the plate,' 22,

in theydesired vertical position. I

To aid in readily locating-the laterally shiftable blind plates,'20, for the purpose of placing the question mark properly, the

upper edge of the slot-carrying plate, 22, is.

marked with-index lines, 22a, with which an index on said plates cooperates. The upper edge of the plate, 22, with its indexes is exposed at the time the lateral shifting or adjustment of blind plates 20, is to be performed, in order to enable the fingers to be passed through the reading slot, 13, to engage =rate whenbase and per cent are known, and

to find percentage when the base and rate are known. In :the'case of percentage parts'of thebelt having percentage problems are exposed and the required indicia are covered "or disclosed.

Instead of using a blind in the sense of an opaque body movable over and away from the symbol, an arrangement-such as shown in Fig. 4 may be employed which includes an electric light placed in rear of the front run of the symbol-carrying apron in the case of each column ofnumerals or symbolsmach light 26'having a handswitch, 27, in its circuit for cutting .it'into and out of circuit andfor each light circuit there is an autom'aticswitch that includes inthe case of each lighta contact, 28, on a horizontal bar, 29,.attached;to the upper end of the pawl bar 1140. The two lights for .the factors 'or members of the problem are cut in circuit by theirhand switches, 27, and the light :for the problem solution has its switch, 27, turned to break the :circuit and accordingly while the other two lights illuminate their respective symbols topresent the problem, the light for the solution is. cut .in circuit only when the solution to the problem is to be revealed, .the action thus corresponding to-the action of the opaque blind device.

What I claim is I 1. An educational device comprising a movable carrier of mathematical symbols arranged ina plurality of groups, thesymbols .ofagroup beingin alinement crosswise of the direction of movement of the carrier-and including a syn'ibol to state a problem audits answer, means to display in succession less cooperative relation with different ones of said symbols.

2. An educational device comprising a movable carrier of mathematical symbols ar ranged in a plurality of groups, the symbols of a group being in alinement crosswise of 5 the direction of movement of the carrier and including a symbol to state a problem and its answer, means to display in successionless than all the symbols of a group to state a problem and certain of theremainder of them to give the answer and selective means todetermine which symbol or symbols less than all of a group shall be displayed, comprising a blind shiftable to dilierent positions along theline of the'symbols of a group, and means to move said blind from symbol c011- cealing position to symbol-displaying position. I

3. An educational device comprising a movable carrier of mathematical symbols arranged in a plurality of groups, the symbols of agroup beingin alinement crosswise of the direction of movement of thecarrier and including a symbol to state a problem and its answer, Vmeans to display in succession less than allthesymbols of a group to state a problem and certain of, the remainder of themto give the answer selective means to determine whichsymbol or symbols less than all 7 of a groupshall be displayed, and means simultaneously to shift said carrier toremove' one group from a display position and another group to display position and prevent exhibition of the answer in the group newly shifted to. display position. a

4. An educational device comprising a movable carrier of mathematical symbols arranged in a plurality of groups, the symbols of :a group being in alinement crosswise of thedirection of movement of the carrier and including a symbol to state a problem and its answer, means to displayin succession less than all the symbols ofa group to state a problem and certain of the remainder of them to give the answer-and selective means to determine which symbol or symbols less than all of a group shall be displayed, :a blind shiftable'to difierent positions along the line of V the symbols of a group, and common. operating means to move said carrier and said blind. I

5. An'educational device comprising means to display a mathematical problemand its solution in succession, including a symbol carrier containing a pluralityof such problems and their solution, means to movethe carrier step by step, and means to move said carrier continuously at difierent times.

6. An educational device comprising means to display a mathematical problem and its solution in succession, including a symbol carrier'containing a plurality of such problems and their solutions arranged in parallel rows, the carrier being movable crosswise of therows, and selective means to present selected symbols of a row in display position ent ones of said symbols.

7. An educational device comprising means to displaya mathematical problem and its solution in succession, including a symbol carrier containing a plurality of such problems and their solutions arranged in parallel" rows, the carrier being'movable crosswise of the rows, and a blind movable crosswise oil the rows and adjustable to lengthen or shorty en its effective area. p

8. An educational device comprising means to display a mathematical problem and its solution in succession, including a symbol carrier containing a plurality of such problems and their solutions arranged in parallel rows, the carrier being movable crosswise of the rows, a blind device, and a carrier for it movable crosswise of the rows onwhich carrier said device is shiftable lengthwise of the rows.

9. An educational device comprising means to display a mathematical problem and its solution in succession, including a symbol carrier containing a plurality of such problems and their solutions arranged in parallel rows, the carrier, being movable crosswise of the rows, and awmovable member having a plurality of display openings said member being shiftable to interchange the positions of such openings.

10. An educational device comprisingcarrier containing a plurality of such problems andtheir solutions arranged in parallel rows, the movement of the carrier being crosswise of the rows, a blind device comprising a i frame extending parallel with the rows and slottedplates slidable on said frame in the directionof length of the rows and with reference to one another and means to move said carrier crosswise of a row. I

11. An educational device comprising a casing havinga sight opening, a symbol carrier in the form of a traveling band, the symbols being in groups, the symbols of a group extending crosswise of the direction of movement of the band and the groups extending in the direction of movement of the band,

hand-operated means to move the band to present the groups in succession at the sightopening, a blind connected with such means and thereby shiftable to and from the sight opening and a plate with groups of display slots interposed between the blind and the sight opening 7 and shiftable to selectively place such groups of slots at the sight opening.

In testimony whereof I hereunto alfix my signature. i

FRANK J SEWALL. 

